Patent GB-1077961-A (GB)
Title: Automatic door opening system
Inventor: WATKINS CECIL JAMES
IPC: E05F15/04
Filed: 1963-03-20
Abstract: 1,077,961. Door operating mechanisms. UNICOST AUTODOORS Ltd. March 20. 1964 [March 20, 1963], No. 44723/62. Heading E2M. [Also in Division F2] An electrical relay controlled door operating system comprises an operating unit 56 mounted in the floor beneath the door and first and second control means acting through a relay system incorporating a timing device for delaying the door in its open position after opening in either direction and holding it in the open position for a further delay period if either control is operated during operation of the door. The operating unit 56 consists of a double acting fluid pressure cylinder 22 with a piston 18 connected via rod 20 to a rack 60 operating a pinion 58 attached to vertical spindle 12 keyed to the door 2. Solenoid operated valves 31, 33 control the cylinder 22 to open the door in either direction from a central position of the piston 18, at which position the door is held by a spring loaded ball 28 engaging with a notch in the rack, and in the de-energised state are exhausted to allow manual opening of the door in an emergency or power failure. On operation of either valve 31 or 33 the piston will move and so move rack 60 which rotates the pinion 58 and opens the door to one of the open positions, the door remaining in this open position until the end of the delay period and is closed by the action of springs 24 or 25. The control system consists of two control switches 42, 44 which may take the form of sensing pads or photoelectric trip switches, four relays 32, 34, 36, 38, and a timing device 40 which contains a condenser and rectifier the discharge of the condenser controlling the delay period, the whole control system being connected to an alternating current supply 46. Operation of control 42 energises the solenoid 10 of relay 32 causing momentary connection of contacts 6, 8 and 1. 3 which in turn charge the condenser and energise solenoid 10 of relay 34 which connects contacts 3, 4 and disconnects contacts 5, 8 of relay 34. The condenser then discharges through the solenoid 10 of relay 34, and operates valve 31, at a predetermined rate to allow for opening of the door and a delay period, at the end of which time solenoid 10 of relay 34 is de-energised, the switch contacts return to their original position and the door closes under the action of the spring means. If, while in the open position control 44 is operated, all that will result will be the recharging of the condenser, for contacts, 5. 8 of relay 34 will be broken due to energisation of solenoid 10 of relay 34 and this relay will not be able to operate the valve 33 to effect movement of the door. The door will remain for a further period of time after which it will close under the action of the spring. The controls 42, 44 are arranged either side of the door and operate to move the door away from the operator. Alternative resilient means may be provided to close the door, and bump stops included to reduce slamming at the end of the opening movements. A bleed control is incorporated in the valve 31, 33 to control exhausting air and hence control the closing speed of the door.